HYDRAULIC SPIKE PULLER

• US 20130240806A1
• Filed: 03/14/2012
• Published: 09/19/2013
• Est. Priority Date: 03/14/2012
• Status: Active Grant

• Current Assignee: Stanley Black & Decker, Inc.
• Original Assignee: Stanley Black & Decker, Inc.
• Inventors: Crover, Stephen
• Granted Patent: US 9,145,648 B2
• Time in Patent Office: Days
• US Class Current: 254/18
• CPC Class Codes: B25B 33/00 Hand tools not covered by any other group in this subclass
• CPC Class Codes: B25B 7/00 Pliers; Other hand-held gripping tools with jaws on pivoted limbs; Details applicable generally to pivoted-limb hand tools implements for fastening, connecting, or tensioning wire or strip B25B25/00; adapted for other fitting or separating purposes B25B27/00; for marking animals A01K11/00; dentists' forceps A61C3/00; bending wire eyes B21F1/06; hand-held metal-shearing or metal-cutting devices B23D29/00; hand cutting tools B26B; for punching or perforating B26F1/36; devices for securing ends of binding material in bundling machines B65B13/24; specially designed for watch-making or comparable work G04D1/00
• CPC Class Codes: B25B 9/00 Hand-held gripping tools other than those covered by group B25B7/00 wrenches B25B13/00; specially adapted for watchmakers' or like use G04D
• CPC Class Codes: B25C 11/00 Nail, spike, and staple extractors incorporated in hammers B25D1/00
• CPC Class Codes: E01B 29/26 the fastening means being spikes E01B29/16 takes precedence; hand-held tools for nail or staple driving or extracting B25C
• CPC Class Codes: Y10T 29/49822 by applying force

Abstract

A pulling tool includes a housing and a tube disposed within the housing, the tube configured to supply hydraulic fluid. The spike puller further includes a piston rod connected to a piston. The piston rod has a hollow axial bore, and the piston and the piston rod are axially moveable relative to the tube. The spike puller has a passage communicating fluid from the tube to the piston. The passage is contained within the housing. The passage is variable between a first configuration in which hydraulic fluid flows at a first restricted flow so as to provide a slower retraction of the piston rod and a second configuration in which hydraulic fluid flows at a second less restricted flow so as to provide a faster retraction of the piston rod.

Claims

1. A pulling tool comprising:

a housing;

a tube disposed within the housing, the tube configured to supply hydraulic fluid;

a piston rod connected to a piston, the piston rod having a hollow axial bore, the piston and the piston rod being axially moveable relative to the tube;

a passage communicating fluid from the tube to the piston, the passage being contained within the housing,

wherein the passage is variable between a first configuration in which hydraulic fluid flows at a first restricted flow so as to provide a slower retraction of the piston rod and a second configuration in which hydraulic fluid flows at a second less restricted flow so as to provide a faster retraction of the piston rod.

2. The pulling tool according to claim 1, wherein the passage is inside a boundary defined by an internal surface of the housing against which the piston is configured to slide.

3. The pulling tool according to claim 1, wherein the piston rod is moveable relative to the tube from a first position to a second position, wherein in the first position hydraulic fluid flows at the first restricted flow, and in the second position, hydraulic fluid flows at the second less restricted flow.

4. The pulling tool according to claim 1, further comprising a head portion and a bottom portion capping the housing, wherein the tube is connected to the head portion.

5. The pulling tool according to claim 4, wherein the tube extends axially from the head portion through the hollow axial bore of the piston rod.

6. The pulling tool according to claim 1, further comprising a jaw assembly adapted to clamp a spike, wherein the piston rod is further connected to the jaw assembly.

7. The pulling tool according to claim 1, further comprising a check valve disposed at an end of the hydraulic tube.

8. The pulling tool according to claim 7, wherein the check valve comprises a sleeve member and a biasing member disposed around a lower portion of the hydraulic tube, the biasing member configured to bias the sleeve member upwardly.

9. The pulling tool according to claim 1, further comprising a liner disposed inside the hollow axial bore.

10. The pulling tool according to claim 9, wherein the liner is in contact with an internal surface of the hollow axial bore.

11. The pulling tool according to claim 10, wherein the liner has lateral ports aligned to allow hydraulic fluid to exit from the axial bore to actuate the piston.

12. The pulling tool according to claim 1, wherein the piston rod has lateral ports to allow hydraulic fluid to exit from the axial bore to actuate the piston.

13. The pulling tool according to claim 1, wherein the passage is defined at least partially by a space between an external surface of the tube an internal surface of the piston rod.

14. The pulling tool according to claim 13, wherein relative movement between the tube and the piston rod varies the size of the space so as to change the passage from the first configuration to the second configuration.

15. The pulling tool according to claim 1, further comprising:

a check valve disposed at an end of the tube, the check valve comprising a sleeve member; and

a liner disposed inside the hollow axial bore,

wherein an internal dimension of the liner is greater than an external dimension of the sleeve member such that when the sleeve member is concentric with the liner, the sleeve member and the liner define a first annular space that is substantially equal to a difference between the internal dimension of the liner and the external dimension of the sleeve member to allow a first restricted flow of hydraulic fluid therethrough and effect a slower retraction of the piston rod.

16. The pulling tool according to claim 15, wherein an external dimension of the tube is smaller than an internal dimension of the liner such that when the liner is pulled upward past and away from the sleeve member, the hollow tube and the sleeve member define a second annular space that is substantially equal to a difference between the internal dimension of the liner and the external dimension of the tube to allow a second less restricted flow of hydraulic fluid therethrough to effect a faster retraction of the piston rod.

17. The pulling tool according to claim 16, wherein the spike puller is configured to automatically change a speed of retraction of the piston rod after a certain predetermined amount of piston travel.

18. The pulling tool according to claim 17, wherein the predetermined amount of piston travel is controlled by a distance between a lower edge of the liner and a port within the liner for communicating fluid to the piston, or controlled by a size of the second annular space, or both.

19. A method of pulling a workpiece with a dual-stage retraction pulling tool, the pulling tool including a housing, a piston and a piston rod, the method comprising:

flowing hydraulic fluid through a relatively smaller first area within the housing so as to provide a slower movement of the piston and a slower retraction of the pulling tool;

automatically changing an area through which the hydraulic fluid flows from the first area to a second area larger than the first area; and

flowing the hydraulic fluid through the relatively larger second area within the housing so as to provide a faster movement of the piston and a faster retraction of the pulling tool.